AHPCC is available for research and instructional use to faculty and students of any Arkansas university and their research collaborators. Basic services are free.
HPC-SUPPORT@listserv.uark.eduwith a description of your research for AHPCC reporting. You will be sent a name for the project leader field in the form.
Connect to the HPC clusters using an SSH client. Linux and Mac computers have SSH built-in as
ssh (terminal connection) and
scp (file transfer). On Windows, you may use
PuTTY for a simple ready-to-run executable.
From the PuTTY website, you will want
psftp.exe, and for graphical connections
plink.exe. There is also an installable program
sshwinsecureshell-3.2.9.exe with an explorer-like file transfer GUI. You may also install Cygwin for a (large in disk usage) clone of the Linux environment in Windows. SSH is not automatically installed, it is an option that must be selected in Cygwin setup.
Login hosts are
trestles.uark.edu, which connect to separate clusters and filesystems. Each login host is a load-balancer of 2 or 3 hosts with a single interface to the outside internet. Your hostname reported by the system after logging in will be similar to
tres-l1. To log in using
ssh and your choice of cluster and UArk or AHPCC-assigned loginname:
ssh trestles.uark.edu -l loginname
ssh razor.uark.edu -l loginname
and the system will prompt for your password. PuTTY and ssh.com SSH have GUIs in which to enter the host name, the login name, and the password.
For everyone that has a UArk identity or email address, your password is your UArk password. AHPCC doesn't know it, can't access it, and won't ask for it. The login host does not keep your password but gets a yes/no decision from an UITS server. Three failed logins in succession will lock your account for 15 minutes. Use UITS facilities such as password.uark.edu or HelpDesk to change password. For non-UArk users, we maintain a password file and can reset the password on request and email it via secure website. No passwords will be requested by AHPCC staff at all, and none will be sent by email.
Usually you will want to copy in some data files to the cluster to run a job, and copy back results after the job runs. SCP is a file transfer implementation built on SSH and is
scp in Linux/Mac/Cygwin and
pscp in PuTTY. To copy
program.c from your workstation to your cluster home area:
scp program.c email@example.com:/home/loginname/
To copy an entire directory tree
src using SCP, use
-r for recursive:
scp -r src firstname.lastname@example.org:/home/loginname/
In SCP, a string containing
: is a remote destination. Just reverse remote and local destination to bring a file back from the cluster. If you don't specify a full path for the local destination, use
./ for the current local directory:
scp -r email@example.com:/home/loginname/src ./
SFTP is an implementation of the FTP command set over SSH. Use
sftp in Linux/Mac/Cygwin and
psftp in PuTTY:
RSYNC is built on top of PSCP and has advantages like preserving modification times and checking to see that the files actually show up at the destination. RSYNC is available on Linux/Mac/Cygwin but is not part of PuTTY or ssh.com SSH. cwRsync is one free version for Windows. RSYNC is most useful for copying or updating entire directory trees.
rsync -av src firstname.lastname@example.org:/home/loginname/
Very large data files should be sent to/from
tgv.uark.edu if on-campus or
dm.uark.edu if off-campus, since these nodes have faster network connections and faster connections to parallel storage.